High-speed Solenoid Valve Research Articles

HYDRAULIC BLOW PRESSURE – AN ALTERNATIVE TO WATER PRESSURE IN HYDROELECTRIC POWER STATIONS

The article shows that an increase in the pressure of the water flow in the hydraulic system after a hydraulic shock (water hammer) can be used to rotate the hydroturbine of a power plant in the same way as when the water pressure is increased in dam hydroelectric plants. The possibilities of using accumulators to stabilize the pressure and flow rate of water after a water hammer are shown. The basic laws of the course of complete and incomplete hydroblow are considered. The advantages of hydraulic shock power plants in comparison with dam hydroelectric power stations and with all other power plants of the same capacity are disclosed. Indisputable advantages include, first of all, the absence of the need for energy consumption from external sources, low costs for design, manufacture and operation. The inertia forces of a constant volume of circulating water are used as a source of renewable energy. The small dimensions of hydroshock power plants make it possible to use them directly in the place of electricity consumption, therefore losses during its transportation are excluded. Water hammer power plants do not affect environmental changes, do not pollute water, air and soil. By regulating the operation of the valves, it is possible to significantly increase the power output of the power plant using modern high-speed solenoid valves or electric valves, which are turned on and off according to a given program. The possibility of using the developed hydraulic shock installation to rotate a bucket hydraulic turbine and generate electricity is being investigated. The widespread introduction of high-impact hydroelectric power plants will permanently get rid of the use of expensive energy sources and keep the human environment clean.

Experimental study on a solenoid valve-based generator for droplet generation

An on-demand droplet generator is developed based on a high-speed and 2-way solenoid valve and studied experimentally in this paper. It is found that the valve-based droplet generator has good controllability, repeatability and stability. Under a suitable applied pressure, a single droplet can be generated by opening the valve with a short voltage pulse. Besides, the droplet size can be conveniently controlled by the applied liquid pressure and pulse width of the control signal. The results show that the present device successes to avoid the limitation of an appropriate outlet pressure required at nozzle tip for most droplet generators in the literature and is capable of producing droplets in a wide size range for a fixed nozzle diameter.

Temperature and frequency dependence of electrical iron effects on electromagnetic characteristics of high-speed solenoid valve for common rail injector

Temperature and frequency dependence of electrical iron effects on electromagnetic characteristics of high-speed solenoid valve for common rail injector

Enhancement Method of Surface Acoustic Wave-Atomizer Efficiency for Olfactory Display

Since olfaction is an important sense in human interfaces, we have developed an olfactory display using a surface acoustic wave (SAW) atomizer and micro-dispensers. In this olfactory display, the efficiency of atomization is important in order to avoid smell persistence problems often encountered in human olfactory interfaces. Thus, the SAW device is coated with amorphous Teflon film to change the substrate nature from hydrophilic to hydrophobic. It is also necessary to silanize the piezoelectric substrate surface prior to Teflon coating to enhance the adhesion of the film. A dip coating method was adopted to obtain uniform coating on the substrate. The high-speed solenoid valve was used as micro-dispenser to spout a liquid droplet to the SAW device surface since its accuracy and reproducibility were high. Then, the atomization became easier on the hydrophobic substrate. In this study, the amorphous Teflon coating for minimizing the remaining liquid on the substrate after atomization was studied. The goal of the protocol described here is to show the methods for coating a SAW device surface with amorphous Teflon film and generating the smell using the SAW atomizer and a micro-dispenser, followed by a sensory test.

Enhancement Method of Surface Acoustic Wave-Atomizer Efficiency for Olfactory Display.

Since olfaction is an important sense in human interfaces, we have developed an olfactory display using a surface acoustic wave (SAW) atomizer and micro-dispensers. In this olfactory display, the efficiency of atomization is important in order to avoid smell persistence problems often encountered in human olfactory interfaces. Thus, the SAW device is coated with amorphous Teflon film to change the substrate nature from hydrophilic to hydrophobic. It is also necessary to silanize the piezoelectric substrate surface prior to Teflon coating to enhance the adhesion of the film. A dip coating method was adopted to obtain uniform coating on the substrate. The high-speed solenoid valve was used as micro-dispenser to spout a liquid droplet to the SAW device surface since its accuracy and reproducibility were high. Then, the atomization became easier on the hydrophobic substrate. In this study, the amorphous Teflon coating for minimizing the remaining liquid on the substrate after atomization was studied. The goal of the protocol described here is to show the methods for coating a SAW device surface with amorphous Teflon film and generating the smell using the SAW atomizer and a micro-dispenser, followed by a sensory test.

Optimization of the High-speed On-off Valve of an Automatic Transmission

The response time of the high-speed on-off solenoid valve has a great influence on the performance of the automatic transmission. In order to reduce the response time of the high-speed on-off valve, the simulation model of the valve was built by use of AMESim and Ansoft Maxwell softwares. To reduce the response time, an objective function based on ITAE criterion was built and the Genetic Algorithms was used to optimize five parameters including circle number, working air gap, et al. The comparison between experiment and simulation shows that the model is verified. After optimization, the response time of the valve is reduced by 38.16%, the valve can meet the demands of the automatic transmission well. The results can provide theoretical reference for the improvement of automatic transmission performance.

New proposal of cylinder velocity control circuit by using PWM drive with high speed solenoid valve

New proposal of cylinder velocity control circuit by using PWM drive with high speed solenoid valve

Hold current effects on the power losses of high-speed solenoid valve for common-rail injector

In the present investigation, a simulation of the dynamic response of a high-speed solenoid valve (HSV) has been performed. The influences of hold current I on the dynamic characteristics and power losses of a HSV have been investigated through the finite-element methods (FEM). The simulation results show that as the driving current I decreases, the opening response characteristics of a HSV deteriorate, the proportion of different power losses decrease in different levels, the energy utilization efficiency of a HSV increases. In the energy distribution of a HSV, core loss accounts for the highest proportion, followed by solid loss and copper loss. Useless energy is mostly due to core loss. It can be concluded that there is a possibility of achieving an optimal balance between the opening response time and energy distribution of a HSV when choosing hold current I properly.

Different boost voltage effects on the dynamic response and energy losses of high-speed solenoid valves

In the present investigation, a simulation of the dynamic characteristics of a high-speed solenoid valve (HSV) was performed using the finite-element method (FEM). The interrelation between power losses and the dynamic response of the HSV was investigated based on the FEM simulation model. The relationship between the boost voltage, dynamic response, and power losses was established according to the energy conversion at the HSV system. The simulation results indicated that as the boost voltage increases, the rising rate of the driving current at the solenoid valve increases sharply, which favors the quick opening of the solenoid, while the power losses caused by the eddy current at the iron core increase rapidly. The rapid increase in the energy loss of the eddy current was the main factor that limited the effectiveness of reducing the opening response time of the solenoid valve by increasing the boost voltage. Regarding the energy utilization, an optimal boost voltage existed, where the solenoid valve reached the highest energy utilization efficiency.

Comparative study of all-printed polyimide humidity sensors with single- and multiwalled carbon nanotube gas-permeable top electrodes

We have developed printed capacitive humidity sensors with highly gas permeable carbon nanotube top electrodes using solution techniques. The hydrophobic, porous multiwalled carbon nanotube (MWCNT) network was suitable for gas permeation, and the response of the capacitive humidity sensors was faster than that of a device with a single-walled carbon nanotube (SWCNT) top electrode. The newly developed measurement system consisting of a small measurement chamber, a computer-controlled high-speed solenoid valve, and a mass-flow controller enabled us to vary the ambient relative humidity within 0.1 s. A comparative study of the devices consisting of a 1.1-µm-thick partially fluorinated polyimide dielectric layer and an MWCNT or SWCNT top electrode revealed that the rise time (humidification process) of the device with MWCNTs (0.49 s) in the transient measurement was almost 3 times shorter than that with SWCNTs (1.48 s) owing to the hydrophobic surface of the MWCNTs. A much larger difference was observed during the drying process (recovery time) probably owing to the hydrophilic parts of the SWCNT surface. It was revealed that the response time was almost proportional to the square of the thickness of the polyimide dielectric layer, d, and the sensitivity was inversely proportional to d. The rise time decreased to 0.15 s and a sensitivity per unit area of 12.1 pF %RH−1 cm−2 was obtained in a device with 0.6-µm-thick polyimide and MWCNT top electrodes. This value is suitable for use in high-speed humidity sensors to realize a real-time humidity and breath-sensing measurement system.

Investigation on Electromagnetic Models of High-Speed Solenoid Valve for Common Rail Injector

A novel formula easily applied with high precision is proposed in this paper to fit the B-H curve of soft magnetic materials, and it is validated by comparison with predicted and experimental results. It can accurately describe the nonlinear magnetization process and magnetic saturation characteristics of soft magnetic materials. Based on the electromagnetic transient coupling principle, an electromagnetic mathematical model of a high-speed solenoid valve (HSV) is developed in Fortran language that takes the saturation phenomena of the electromagnetic force into consideration. The accuracy of the model is validated by the comparison of the simulated and experimental static electromagnetic forces. Through experiment, it is concluded that the increase of the drive current is conducive to improving the electromagnetic energy conversion efficiency of the HSV at a low drive current, but it has little effect at a high drive current. Through simulation, it is discovered that the electromagnetic energy conversion characteristics of the HSV are affected by the drive current and the total reluctance, consisting of the gap reluctance and the reluctance of the iron core and armature soft magnetic materials. These two influence factors, within the scope of the different drive currents, have different contribution rates to the electromagnetic energy conversion efficiency.

Control system design for proton exchange membrane fuel cell based on a common rail (II): Optimization and schedule scheme for the common rail

Conduction ratio and switching frequency are two main factors influencing the reliability and durability of high-speed solenoid valves in common rail hydrogen injection systems. Excessive conduction ratio may result in valve overheating, while the switching frequency determines the lifespan of the valve, which should be scheduled evenly for each valve. In this paper, first, a minimum nozzle configuration scheme is presented to optimise a given common rail for the minimum number of valves. Second, two strategies to equalise and optimise the workload (conduction ratio and switching frequency) of each valve are developed: 1) the circular queue schedule strategy ensures uniform workload of each valve and 2) the circular queue with random rotation schedule strategy can further decrease the switching frequency drastically by introducing randomness. Finally, both the minimum nozzle configuration scheme and the schedule strategies are elaborately analysed and verified via simulations. The circular queue with random rotation strategy with a probability of 0.99 shows superior performance.

System Modeling and Pressure Control of a Clutch Actuator for Heavy-Duty Automatic Transmission Systems

Precision control of clutch pressure is critical in heavy-duty automatic transmission applications in which the fast response of the clutch actuator is required. A conventional clutch actuator system with a pressure-reducing valve (PRV) is not applicable in this kind of application due to the fact that a large transient flow and high output power for power-on shift are necessary. In this paper, a pilot-operated PRV is developed for heavy-duty automatic transmission systems. The developed PRV can make the clutch actuator system have a fast response and a high flow capacity simultaneously. The PRV utilizes a three-stage structure with a high-speed proportional solenoid valve (PSV) as the pilot stage to do the tradeoff between the valve response and the flow capacity. First, a linearized input–output dynamic analytical model for the clutch pressure control system is developed based on fluid dynamics. Then, the parameters are identified, and the model is validated by using experimental data. For the validated input–output model, both open- and closed-loop (feedback) pressure control strategies are designed and implemented in a test setup. It infers from the experimental results that the feedback control can lead to excellent control precision. The developed clutch actuator system is applicable for heavy-duty automatic transmissions.

高速電磁弁を用いた空気圧シリンダの速度制御に関する研究

In general, the speed control of the pneumatic cylinder constituting the meter-out circuit. The speed controller is used at that time. But, its adjustment is difficult for manual operation. For that reason, we propose the high speed solenoid valve instead of the speed controller. The high speed solenoid valve is controlled by constant PWM (Pulse-Width-Modulation). At first, this study makes an investigation into the static characteristic by flow-rate characteristics using isothermal chamber when the high speed solenoid valve is controlled by constant PWM. As result, it has been found that the static characteristic of the high speed solenoid valve is linear. Next, we have examined a speed control of the meter-out circuit with the pneumatic cylinder and the high speed solenoid valve. As result, in the meter-out circuit, the equilibrium velocities calculated from the static characteristics and the measured equilibrium velocities are the nearly values. So, we obtain that the speed control of the pneumatic cylinder is possible at the high speed solenoid valve.

Impact Of The Pulse Width Modulation On The Temperature Distribution In The Armature Of A Solenoid Valve

In order to estimate the inductive power set in the armature of the high-speed solenoid valve (HSV) during the open loop control (OLC) using pulse width modulation (PWM) an analytical explicit formula has been derived. The simplifications taken both in the geometry and in the physical behavior of the HSV were described. The inductive power was calculated for different boundary conditions and shown as a function of the frequency of the coil current. The power set in the armature was used as an input to the thermal calculation. The thermal calculation had an objective to estimate the time dependent temperature distribution in the armature of the HSV. All the derivation steps were presented and the influence of different boundary conditions was shown and discussed. The increase of the temperature during the heating with inductive power has been evaluated both in the core and on the side surface of the HSV.

Dynamic performance of high speed solenoid valve with parallel coils

The methods of improving the dynamic performance of high speed on/off solenoid valve include increasing the magnetic force of armature and the slew rate of coil current, decreasing the mass and stroke of moving parts. The increase of magnetic force usually leads to the decrease of current slew rate, which could increase the delay time of the dynamic response of solenoid valve. Using a high voltage to drive coil can solve this contradiction, but a high driving voltage can also lead to more cost and a decrease of safety and reliability. In this paper, a new scheme of parallel coils is investigated, in which the single coil of solenoid is replaced by parallel coils with same ampere turns. Based on the mathematic model of high speed solenoid valve, the theoretical formula for the delay time of solenoid valve is deduced. Both the theoretical analysis and the dynamic simulation show that the effect of dividing a single coil into N parallel sub-coils is close to that of driving the single coil with N times of the original driving voltage as far as the delay time of solenoid valve is concerned. A specific test bench is designed to measure the dynamic performance of high speed on/off solenoid valve. The experimental results also prove that both the delay time and switching time of the solenoid valves can be decreased greatly by adopting the parallel coil scheme. This research presents a simple and practical method to improve the dynamic performance of high speed on/off solenoid valve.

The Simulation Analysis of the High Speed Switch Valve Control the Cartridge Valve Based on AMEsim

To establish the mathematical model of the system of high speed switch valve control the cartridge valve based on analyzing the working principle of the system,and then to analyze the impact of selecting different input signal of high speed solenoid valve and different duty cycle of PWM pulse width modulated signal through simulation software AMSEsim. The results obtained in the high-frequency performance is not very satisfactory, but in the low signal and moderate duty cycle, high-speed switch valve can be good linear control of the cartridge valve.

Research on key factors and their interaction effects of electromagnetic force of high-speed solenoid valve.

Analysis consisting of numerical simulations along with lab experiments of interaction effects between key parameters on the electromagnetic force based on response surface methodology (RSM) has been also proposed to optimize the design of high-speed solenoid valve (HSV) and improve its performance. Numerical simulation model of HSV has been developed in Ansoft Maxwell environment and its accuracy has been validated through lab experiments. Effect of change of core structure, coil structure, armature structure, working air gap, and drive current on the electromagnetic force of HSV has been analyzed through simulation model and influence rules of various parameters on the electromagnetic force have been established. The response surface model of the electromagnetic force has been utilized to analyze the interaction effect between major parameters. It has been concluded that six interaction factors including working air gap with armature radius, drive current with armature thickness, coil turns with side pole radius, armature thickness with its radius, armature thickness with side pole radius, and armature radius with side pole radius have significant influence on the electromagnetic force. Optimal match values between coil turns and side pole radius; armature thickness and side pole radius; and armature radius and side pole radius have also been determined.

Research on Liner Pressure Control of Force Control System of High-speed Switch Solenoid Valve

Research on Liner Pressure Control of Force Control System of High-speed Switch Solenoid Valve

A facile on-demand droplet microfluidic system for lab-on-a-chip applications

We present a facile microfluidic droplet-on-demand (DOD) system in which a pulsed pressure generated by a high-speed solenoid valve is used to control the formation and movement of water-in-oil emulsion droplets in a T-junction microchannel. We investigated the working principle of the DOD system and established a scaling model for the droplet volume in terms of the amplitude and duration of the pulse and the hydraulic resistance of the injection channel. The droplet formation was characterized in three designs at various pressure pulses. The experimental results support our scaling model very well. In the DOD system we developed, nanoliter-volume droplets with a throughput of a few droplets per second were on-demand generated. Moreover, we examined the applicable scope of the DOD system. As examples of practical applications of the DOD system, we demonstrated a digital display module to show droplets formed at a prescribed time and a droplet array with a concentration gradient to show droplets formed with a precise volume. We expect our work can provide design guidelines for a robust DOD system and improve the capabilities of droplet-based microfluidics in ‘lab-on-a-chip’ systems.